**Core Concept**
Angelman syndrome is a genetic disorder characterized by severe developmental delay, intellectual disability, and a distinctive facial appearance. It is a neurodevelopmental disorder caused by a deficiency in the function of the UBE3A gene, which is normally active in the brain.

**Why the Correct Answer is Right**
The UBE3A gene is located on chromosome 15, specifically on the maternal copy (15q11.2-q13). The mutation or deletion of this gene leads to a decrease in the expression of the UBE3A protein, resulting in the characteristic symptoms of Angelman syndrome. The paternal copy of the UBE3A gene is typically silenced due to genomic imprinting, making the maternal copy essential for normal brain development.

**Why Each Wrong Option is Incorrect**
* **Option A:** This is incorrect because it is not the chromosome associated with Angelman syndrome.
* **Option B:** This is incorrect because it is the chromosome associated with Prader-Willi syndrome, a different genetic disorder.
* **Option C:** This is incorrect because it is not a correct chromosome associated with Angelman syndrome.

**Clinical Pearl / High-Yield Fact**
Angelman syndrome is often referred to as "happy puppet syndrome" due to the characteristic facial expression and stiff gait of affected individuals. It is essential to differentiate Angelman syndrome from Prader-Willi syndrome, which has distinct clinical features and diagnostic criteria.

**Correct Answer: D. Chromosome 15.**